Review: Myeloid Disorders Flashcards
What is the pathogenesis of problems caused by Acute Leukemias?
In Acute Leukemias/lymphomas, a proliferation of -blasts causes what?
Suppression of NL hematopoeisis
- Anemia
- 2. Thrombocytopenia
- 3. Neutropenia
What are differences seen in ALL and AML?
- ALL
- Lymphoblasts (TdT+)
- Children
- T-ALL = teenager and thymic mass
- AML
- Myeloblasts (MPO+ and auer rods)
- Older people >60
Myeloblasts are positive for what marker?
MPO (=> auer rods)
Markers for AML
- CD33+
- CD34+
Acute Myeloid Leukemia (AML)
Malignant proliferation of myeloblasts in the BM.
- Released into bloodstream = leukocytosis
- Fill up BM => supress of NL hematopoeisis (pancytopenia)
- Anemia,
- Thrombocytopenia
- Neutropenia
- M5 = gum infiltation (gingival hyperplasia)
In order to qualify as AML, on biopsy of the BM what must we see?
at least 20% of BM is myeloblasts
AML is MC in who?
- >60 YO Males
- If in younger adults: balanced translocations
- t(8:21)
- inv(16)
- t(15:17)
Most genetic abnormalities in AML..
- Most genetic abnormalities in AML interfere with TF that are required for NL myeloid cell to differentiate.
- Karyotypic aberrations are found in 90% of cases
Most common chromosomal rearrangements in AML
- t(8:21): disrupt RUNX1 gene (M2) ***
- inv(16): disrupt CBFB gene (M4) **
- t(15;17): PML- RAR-a fusion gene (Acute Promyelocytic Leukemia/M3); + FLT3 activating mutation
- t(11q23;v): involve MLL (M4/5)
RF for AML
- Alkylating chemotherapy
- Radiation
- MPD
- Down Syndrome (Also RF in ALL)
Clinical Presentation of Acute Myeloid Leukemia
Present with similar clinical picture as ALL: sx of pancytopemia
- Anemia = >Fatigue (anemia)
- Neutropenia => fever/ Opportunistic infections (fungi, pseudomonas, commensals and pneumocystis) of oral cavity, skin GI/GU tract.
- Thrombocytopenia => spontaneous mucosal and cutaneous bleeding (worse in APML)
- Petechiae, ecchymoses, mucosal hemorrhages and hematuria
M5 = AML with monocytic differentiation = gingival swelling and skin infiltration (leukemia cytis)
What are differences in clinical presentation of ALL and AML?
AML is LESS likely to present with (but still CAN)
- Bone pain
- LAD
- Hepatosplenomegaly
- CNS/testes spread
- Rarely presents as a mass
Diagnosis of Acute Myeloid Leukemia
- Myeloid specific antigen stains (MPO and non-specific esterases)
- BM exam is REQUIRED = >20% of myeloblasts in BM
WHO Classification of AML: Class 1, 2 and 3
What is Class I AML?
Prognosis?
AML + genetic aberrations
Favorable prognosis:
- t(8:21),
- inv(16)
Intermediate prognosis:
- t(15;17)
Poor prognosis:
- t(11;q23:v)
WHO Classification of AML: Class 1, 2 and 3
What is Class 2 AML?
Prognosis?
AML with MDS-like features
All have poor prognosis
- AML due to prior MDS
- MDS-like cytogenic aberrations
WHO Classification of AML: Class 1, 2 and 3
What is Class 3 AML?
Prognosis?
AML that is therapy related
All VERY POOR prognosis
- AML due to alkylating chemo/radiation
- Post- topoisomerase-II inhibitrs
What are the FAB Classification of AML?
- M0 =
- M1 =
- M2=
- M3 =
- M4 =
- M5a/b =
- M6a/b =
- M7 =
- M0 = Minimally differentiated AML
- M1 = AML without maturation
- M2= AML with myelocytic maturation
- M3 = Acute Promyelocytic Leukemia
- M4 = Acute myelomonocytic Leukemia (with myelomonocytic maturation)= AMML
- M5a/b = Acute Monocytic Leukemia (with monocytic maturation)
- M6a/b = Acute Erythroleukemia (with erythroid maturation)
- M7 = Acute Megakaryotic Leukemia (with megakaryocytic maturation)
Name this classifcation of AML:
Blasts lack cytologic and cytochemical markers of myeloblasts
M0 - AML, minimally differentiated
What do you see in
M1: AML without maturation
20% of cases
Very immature cells
- >3% are MPO(+)
- Few granules or Auer rods
What do you see in
M2: AML with myelocytic maturation
- t(8:21) = MC type (30-40%)
- All granulocytes have undergone myeloid maturation
- Auer rods are present
What do you see in
M3: Acute Promyelocytic Leukemia
- Pts are younger (35-40 yo)
- Most cells are hypergranular promyelocytes
-
t(15:17) with FLT3 activating mutation => PML-RARA fusion gene
- Chr 15 = Retinoic acid receptor- alpha (RARA) is dysfunctional: prevents NL maturation of promyelocytes => INC amounts of promyelocytes, which contains MANY Auer rods => if they leak out of cell => INC risk of DIC
What is the treatment for Acute Promyelocytic Leukemia?
All trans-retinoid acid (form of Vitamin A): ABNL cells will mature
What do you see in
M4: with myelomonocytic maturation (Acute myelomonocytic Leukemia/ AMML)
- Inv(16)
- Cells = Myelocytic and monocytic differention
- Myeloid cells = MPO +
- Monoblasts = Non-specific esterase (+), no auer rods and MPO (-)